The aircraft records indicated that the aircraft was certified and equipped for the flight and there was no evidence found of any system malfunction during the flight. The crew were certified and qualified for the flight and although they were on their second trip during a long day, the duty times were within allowable guidelines. However, several other factors combined in this occurrence to create a situation where the crew inadvertently did not complete the pre-landing check and then did not recognize the landing gear warning when it activated prior to the attempted landing. The flight was prolonged because the weather at the oil rig was too poor to allow for landing and refuelling. This placed the crew in the situation where they were unable to accomplish the intended mission and while they had sufficient fuel in accordance with regulations, the available time and options for the return flight were now more restrictive than if they had landed at the rig and refueled. The flight proceeded uneventfully while returning to St. John's. Air traffic control clearance to the airport and then for descent were received while the aircraft was still a substantial distance from landing, and as a result, the pre-landing check was delayed until the aircraft was closer to landing. The crew were advised of the weather conditions and found the ceiling and visibility were decreasing and were expected to be near approach limits by the time that they arrived, which further restricted their options. The crew were aware that other higher speed aircraft were following them on the approach and the decision was made to maintain their cruising speed and delay slowing down to their normal approach speed. In this now time-restricted context, the crew received their overshoot instructions which would require them to go-around and set up for another approach. The crew knew the weather was slightly better at their alternate of Long Pond. The captain decided that if the approach was unsuccessful he wanted to overshoot and proceed to Long Pond rather than expend precious fuel and time on an extended procedure to re-attempt an approach that had already been unsuccessful. When the captain expressed this desire to air traffic control the controller did not initially comprehend what the captain was requesting and it took several radio transmissions to get things sorted out. This conversation took place during the time that the crew were transitioning to final approach between 11 and 6 miles from touchdown. The pre-landing check would normally have been completed at approximately this point during the approach and it is likely that the discussion regarding the missed approach intentions provided enough of a distraction that the crew missed completing the pre-landing check that they had previously delayed. Shortly thereafter and just prior to the aircraft intercepting the ILS glidepath, the crew was instructed to change to the St. John's tower radio frequency. The aircraft then intercepted the glidepath and, because of the higher than ideal speed, the aircraft went high on the glidepath, which required the crew to make several power adjustments to slow down and then regain the desired approach profile. Despite having an automatic flight control system, the workload for both crew members would be high in this situation, and it is likely that the successful completion of the approach became a primary focus for the crew. The crew regained the ideal ILS glidepath shortly before the decision height of 549 feet on the barometric altimeter. Just prior to reaching decision height the captain acquired visual reference and assumed manual control of the aircraft to conduct the landing. The crew were conducting the Category 1 ILS approach to a 100 foot decision height in accordance with the Transport Canada operations specification, and with no radar altimeter reference heights on the instrument approach procedure chart, the radar altimeter altitude alert was set to the published HAT of 100 feet. When the aircraft reached decision height it was still 164 feet above ground and therefore the radar altimeter altitude warnings activated, sometime after decision height was reached, during the time that the captain had assumed manual control and was slowing down and flaring for the touchdown. The landing gear warning system is activated whenever the landing gear is retracted, the radar altimeter senses that the aircraft is below 300 feet above ground, and the airspeed is 60 knots or less. When the aircraft reached decision height it was below 300 feet above ground but it was travelling faster than 60 knots so the landing gear warning had not yet activated. The warning system activated sometime during the time that the captain was slowing down and flaring for the touchdown. To carry out the landing the captain was flying by visual references which required looking ahead through the windshield and not directly at the instrument panel. With the prevailing low visibility conditions this manoeuvre required a high level of concentration on the part of the captain. The red warning lights for the radar altimeter and the landing gear warning are located in the lower portion of the instrument panel and during the landing they would both be at the lower edge of the captains peripheral vision. It is possible that the captain was concentrating on the visual landing manouevre to the extent that, when these visual warnings illuminated in his peripheral vision, they were either not noticed, or were interpreted as the radar altimeter warning which would be a normal event during the landing sequence. After the captain acquired visual reference and took control, the co-pilot was dedicated to monitoring the flight instruments and calling out altitudes and airspeeds for the captain until a stable hover or touchdown was achieved. The red warning lights for the radar altimeter and the landing gear warning are located in the lower portion of the instrument panel on the co-pilot's instrument panel as well. The landing gear control panel, with the gear position indicators, was well out of the co-pilot's field of view on the opposite side of the centre console next to the captain's left knee. The co-pilot did not recognize the landing gear warning when it activated and while it is likely that the co-pilot misinterpreted the visual warnings, an explanation for this phenomenon could not be determined. The aural warnings for the radar altimeter and landing gear warning systems were close in frequency and both were non-pulsating constant frequency tones. It was discovered that these tones could easily be misinterpreted as one tone should they activate concurrently or in overlapping succession. These tones were heard by the crew through their headsets. At the approximate time that the tones would have activated several verbal calls were being made by the co-pilot and likely some verbal acknowledgements were being made by the captain as he was conducting the landing. It is very likely that both warning systems activated at or about the same time and the crew interpreted them as the radar altimeter warning. A radar altimeter warning would be an expected event during the course of a normal landing procedure and as such would not trigger the crew to change their course of action. While there was no direct indication of the events inside the cockpit, such as could have been provided by the CVR, the factors and data relating to the occurrence indicate that while operating in a high-workload, time-restricted environment the crew inadvertently did not recall that the pre-landing check was not yet completed before attempting the landing. It is also most likely that the radar altimeter and landing warnings occurred in close succession and because of their similar characteristics were misinterpreted as an anticipated and non-critical advisory, in which case the landing gear warning went unrecognized. The following Engineering Branch reports were completed:Analysis The aircraft records indicated that the aircraft was certified and equipped for the flight and there was no evidence found of any system malfunction during the flight. The crew were certified and qualified for the flight and although they were on their second trip during a long day, the duty times were within allowable guidelines. However, several other factors combined in this occurrence to create a situation where the crew inadvertently did not complete the pre-landing check and then did not recognize the landing gear warning when it activated prior to the attempted landing. The flight was prolonged because the weather at the oil rig was too poor to allow for landing and refuelling. This placed the crew in the situation where they were unable to accomplish the intended mission and while they had sufficient fuel in accordance with regulations, the available time and options for the return flight were now more restrictive than if they had landed at the rig and refueled. The flight proceeded uneventfully while returning to St. John's. Air traffic control clearance to the airport and then for descent were received while the aircraft was still a substantial distance from landing, and as a result, the pre-landing check was delayed until the aircraft was closer to landing. The crew were advised of the weather conditions and found the ceiling and visibility were decreasing and were expected to be near approach limits by the time that they arrived, which further restricted their options. The crew were aware that other higher speed aircraft were following them on the approach and the decision was made to maintain their cruising speed and delay slowing down to their normal approach speed. In this now time-restricted context, the crew received their overshoot instructions which would require them to go-around and set up for another approach. The crew knew the weather was slightly better at their alternate of Long Pond. The captain decided that if the approach was unsuccessful he wanted to overshoot and proceed to Long Pond rather than expend precious fuel and time on an extended procedure to re-attempt an approach that had already been unsuccessful. When the captain expressed this desire to air traffic control the controller did not initially comprehend what the captain was requesting and it took several radio transmissions to get things sorted out. This conversation took place during the time that the crew were transitioning to final approach between 11 and 6 miles from touchdown. The pre-landing check would normally have been completed at approximately this point during the approach and it is likely that the discussion regarding the missed approach intentions provided enough of a distraction that the crew missed completing the pre-landing check that they had previously delayed. Shortly thereafter and just prior to the aircraft intercepting the ILS glidepath, the crew was instructed to change to the St. John's tower radio frequency. The aircraft then intercepted the glidepath and, because of the higher than ideal speed, the aircraft went high on the glidepath, which required the crew to make several power adjustments to slow down and then regain the desired approach profile. Despite having an automatic flight control system, the workload for both crew members would be high in this situation, and it is likely that the successful completion of the approach became a primary focus for the crew. The crew regained the ideal ILS glidepath shortly before the decision height of 549 feet on the barometric altimeter. Just prior to reaching decision height the captain acquired visual reference and assumed manual control of the aircraft to conduct the landing. The crew were conducting the Category 1 ILS approach to a 100 foot decision height in accordance with the Transport Canada operations specification, and with no radar altimeter reference heights on the instrument approach procedure chart, the radar altimeter altitude alert was set to the published HAT of 100 feet. When the aircraft reached decision height it was still 164 feet above ground and therefore the radar altimeter altitude warnings activated, sometime after decision height was reached, during the time that the captain had assumed manual control and was slowing down and flaring for the touchdown. The landing gear warning system is activated whenever the landing gear is retracted, the radar altimeter senses that the aircraft is below 300 feet above ground, and the airspeed is 60 knots or less. When the aircraft reached decision height it was below 300 feet above ground but it was travelling faster than 60 knots so the landing gear warning had not yet activated. The warning system activated sometime during the time that the captain was slowing down and flaring for the touchdown. To carry out the landing the captain was flying by visual references which required looking ahead through the windshield and not directly at the instrument panel. With the prevailing low visibility conditions this manoeuvre required a high level of concentration on the part of the captain. The red warning lights for the radar altimeter and the landing gear warning are located in the lower portion of the instrument panel and during the landing they would both be at the lower edge of the captains peripheral vision. It is possible that the captain was concentrating on the visual landing manouevre to the extent that, when these visual warnings illuminated in his peripheral vision, they were either not noticed, or were interpreted as the radar altimeter warning which would be a normal event during the landing sequence. After the captain acquired visual reference and took control, the co-pilot was dedicated to monitoring the flight instruments and calling out altitudes and airspeeds for the captain until a stable hover or touchdown was achieved. The red warning lights for the radar altimeter and the landing gear warning are located in the lower portion of the instrument panel on the co-pilot's instrument panel as well. The landing gear control panel, with the gear position indicators, was well out of the co-pilot's field of view on the opposite side of the centre console next to the captain's left knee. The co-pilot did not recognize the landing gear warning when it activated and while it is likely that the co-pilot misinterpreted the visual warnings, an explanation for this phenomenon could not be determined. The aural warnings for the radar altimeter and landing gear warning systems were close in frequency and both were non-pulsating constant frequency tones. It was discovered that these tones could easily be misinterpreted as one tone should they activate concurrently or in overlapping succession. These tones were heard by the crew through their headsets. At the approximate time that the tones would have activated several verbal calls were being made by the co-pilot and likely some verbal acknowledgements were being made by the captain as he was conducting the landing. It is very likely that both warning systems activated at or about the same time and the crew interpreted them as the radar altimeter warning. A radar altimeter warning would be an expected event during the course of a normal landing procedure and as such would not trigger the crew to change their course of action. While there was no direct indication of the events inside the cockpit, such as could have been provided by the CVR, the factors and data relating to the occurrence indicate that while operating in a high-workload, time-restricted environment the crew inadvertently did not recall that the pre-landing check was not yet completed before attempting the landing. It is also most likely that the radar altimeter and landing warnings occurred in close succession and because of their similar characteristics were misinterpreted as an anticipated and non-critical advisory, in which case the landing gear warning went unrecognized. The following Engineering Branch reports were completed: Aircraft records indicated that the aircraft was certified and equipped for the flight. No evidence was found of any system malfunction during the flight. The crew were certified and qualified for the flight and duty times were within allowable guidelines. The crew delayed the pre-landing check and then while operating in a high-workload time-restricted environment did not notice that the pre-landing check was not yet completed. As there was no radar altimeter reference heights on the Category 1 ILS instrument approach procedure chart, the crew used the HAT of 100 feet and set the radar altimeter altitude alert preset accordingly. The published approach procedure for the Category 2 ILS approach to Runway 29 at St. John's indicates that a decision height of 100 feet HAT corresponds to a barometric altimeter reading of 549 feet above sea level, and a radar altimeter reading of 164 feet above ground. The landing gear warning tone and the radar altimeter warning tone are similar in frequency and duration. The warnings activated by the landing gear warning system were not recognized by the crew. The crew did not recognize that the landing gear was retracted until touchdown was imminent. The nose of the helicopter contacted the runway surface and sustained minor damage.Findings Aircraft records indicated that the aircraft was certified and equipped for the flight. No evidence was found of any system malfunction during the flight. The crew were certified and qualified for the flight and duty times were within allowable guidelines. The crew delayed the pre-landing check and then while operating in a high-workload time-restricted environment did not notice that the pre-landing check was not yet completed. As there was no radar altimeter reference heights on the Category 1 ILS instrument approach procedure chart, the crew used the HAT of 100 feet and set the radar altimeter altitude alert preset accordingly. The published approach procedure for the Category 2 ILS approach to Runway 29 at St. John's indicates that a decision height of 100 feet HAT corresponds to a barometric altimeter reading of 549 feet above sea level, and a radar altimeter reading of 164 feet above ground. The landing gear warning tone and the radar altimeter warning tone are similar in frequency and duration. The warnings activated by the landing gear warning system were not recognized by the crew. The crew did not recognize that the landing gear was retracted until touchdown was imminent. The nose of the helicopter contacted the runway surface and sustained minor damage. The crew intentionally delayed the execution of the pre-landing check and then while operating in a high-workload time-restricted environment the crew inadvertently did not recall that the pre-landing check was not yet completed. Subsequently, the crew did not recognize the landing gear warning prior to attempting to land which resulted in the nose of the helicopter contacting the runway surface while the landing gear was retracted.Causes and Contributing Factors The crew intentionally delayed the execution of the pre-landing check and then while operating in a high-workload time-restricted environment the crew inadvertently did not recall that the pre-landing check was not yet completed. Subsequently, the crew did not recognize the landing gear warning prior to attempting to land which resulted in the nose of the helicopter contacting the runway surface while the landing gear was retracted. Since the occurrence the company has taken several initiatives to reduce the likelihood of a recurrence. Company procedures state that the pre-landing check is now completed at 10 miles from the landing site. The company believes that this is much earlier in the approach phase and as a result should ensure the completion of the pre-landing check at a time when other high priority tasks are not competing with each other for the attention of the pilots. The company has introduced a final landing check that is carried out from memory and silently on short final. The check covers landing gear, warning lights, coupler, radar, engine instruments, bleed valves, and destination. The non-flying pilot carries out the check and reports to the flying pilot the final check is complete. At the time of the occurrence the Long Pond approach was an interim procedure that had been used during previous offshore activities. The approach has since been approved and the company has conducted at least three liaison visits to the air traffic control centre to review unique requirements and alternate landing sites. It was noted that the warning tones for the radar altimeter and the landing gear were similar in frequency and are considered difficult to distinguish when they activate close together. The company is currently investigating optional modifications that may be made to either of these warning systems to make them more distinct.Safety Action Since the occurrence the company has taken several initiatives to reduce the likelihood of a recurrence. Company procedures state that the pre-landing check is now completed at 10 miles from the landing site. The company believes that this is much earlier in the approach phase and as a result should ensure the completion of the pre-landing check at a time when other high priority tasks are not competing with each other for the attention of the pilots. The company has introduced a final landing check that is carried out from memory and silently on short final. The check covers landing gear, warning lights, coupler, radar, engine instruments, bleed valves, and destination. The non-flying pilot carries out the check and reports to the flying pilot the final check is complete. At the time of the occurrence the Long Pond approach was an interim procedure that had been used during previous offshore activities. The approach has since been approved and the company has conducted at least three liaison visits to the air traffic control centre to review unique requirements and alternate landing sites. It was noted that the warning tones for the radar altimeter and the landing gear were similar in frequency and are considered difficult to distinguish when they activate close together. The company is currently investigating optional modifications that may be made to either of these warning systems to make them more distinct.